Spark-plug



C. E. SHERMAN.

SPARK PLUG. APPLICATION FILED MAY 5.1916

Patented Feb. 17, 1920,

. Y I I a m N e R E m m5 My 52 Z w w e n an CHESTER E. SHERMAN, OF KANSAS CITY, MES

UNITED STATES PATENT OFFICE.

sonar, Assreuon Ton. w. COLEMAN,

OF KANSAS CITY, MISSOURI SPARK-PLUG.

Specification of Letters Patent.

Patented Feb. 17, 1920.

Application filed May 5, 1916. Serial No. 95,605.

being had to the accompanying drawings,

and to the letters and marked thereon, which specification.

My invention relates to spark plugs, and more particularly to a device of that character for use in internal combustion engines for igniting the charges of fuel, gases or vapors at regular intervals determined by a commutator that is used in connection with the motor of which the spark plug forms a part, the principal object of the present invention being to provide a plug which will not only effect the customary spark, but will further prepare the fuel for proper and effective ignition.

In accomplishing this object I have provided improved details of structure, the preferred forms of which are illustrated in the accompanying drawings, wherein Figure I is an elevation of a spark plug figures of reference form a part of this constructed according to my invention.

Fig. II is same.

Referring more in detail to the draw- 1ngs:-

1 designates the plug, which comprises a threaded neck 2, that is attached to the cylinder by threading into an aperture in the cylinder wall, and 3 the head of the plug whereby the neck may be threaded into or from the cylinder aperture.

Located within the head 3, is a pocket 4, comprising a shoulder 5 against which the flange 6 of a barrel 7 is adapted to seat when the barrel is projected into the head, the said barrel having a tip 8 eXtendcd into the neck 2. The barrel 7 is adapted for free projection into and removable from the head socket and is held in place by a packing nut 10, having a threaded collar 11, that projects into the upper end of the head socket and bears against the barrel a longitudinal section of the flange tov hold the flange to its seat and securely anchor the barrel to the plug.

The barrel 7 has a central channel 12, and extended through said channel is a core 13 of conductive material that is stiparated from the barrel 7 by insulation 14 0 any suitable nature, the barrel-itself being preferably formed of porcelain in order to form a non-conductive housing and carriage for the core.

l 'Ihe core 13 extends beyond the outer end 0 compression washer 15 and clamp member 16, between which the high tension terminal wire 17 from a battery, or the like, is clamped in order to conduct current to the core. The inner end of the core projects beyond the inner end of the barrel and into a perforated casin 18, past a point 19, that is carried by said casing. The point .19 preferably comprises the. threaded body that attaches to the casing and a reduced terminal 20, which latter is slightly spaced from the core 13 to afford a gap 21 through which a spark must pass at the-ignition periods.

The casing 18 and the plug body is formed of suitable conductive material, the casing being bolted or otherwise secured to the plug body and the body being in conductive relation to the walls 22 of the cylinder to carry the ground current from the wall of the cylinder through the plug body and casing to the point 19 in order to complete a circuit with the high tension core through the spark gap.

The housing 18 is of substantially greater diameter than the core 13 in order to form a chamber 23 within the housing that may contain a substantial quantity of fuel gas.

In using the plug, assuming that it is 8.8- sembled with the cylinder and connected with the battery or magneto, current may flow through the wire 17 to the core 13 and through the cylinder walls to the plug body and casing 16 in the usual manner, the oper-' ation of the plug being the same as with an ordinary device of this character, except that the spark gap is contained within the housing 16, so that vapor or gases must pass through the casing apertures before it can reach the spa k point.

When the engine is in operation, and vapor admitted to the engine cylinder, vapor the barrel 7 and is threaded to carry a proper intervals a circuit is closed through the high tension terminal and the ground terminal and a spark passed between the point that ignites the fuel within the housing. This ignition efiects explosion in the housing that passes ignited gas through the housing apertures to ignite and explode the larger volume of fuel within the body oi the cylinder. After a few explosions have taken place the housing becomes heated, so that the fuel 7 Va or passing through the apertures is trans ormed into a dry gas and is more readily ignited than the ordinary fuel vapor.

Having thus described my invention what I claim as new therein, and desire to Secure by Letters-Patent, is r A spark plug, embodying in its structure a threaded neck for attachment to the cylinder of an engine, an electrode extending longitudinally through the plug and projecting beyond said neck, an elongated perforated casing mounted on the end of said neck and housing the end of said electrode, a second electrode mounted radially in said housing in position to form a spark gap with said first-named electrode, said housing providing a heating element for the gases surrounding the spark gap, and means for adjusting said second electrode relative to said first-named electrode. comprising a threaded radial opening in the casing, adapted to receive an exteriorly threaded portion on the electrode.

In testimony whereof I ailix my signature.

CHESTER E. SHERMAN. 

